We are currently attempting to locate the primary, genetic lesion in the obese-hyperglycemic mouse as well as investigating the interrelationship of the obesity to the hyperglycemia and hyperinsulinemia observed in these animals. The role of diet in the determination of metabolic patterns in various forms of genetic obesity and experimentally induced obesity will also be investigated. The studies will include the endocrinological aspects as well as the metabolic adaptations to high fat diets and diets with different carbohydrate sources.